@import url('https://fonts.googleapis.com/css2?family=Manrope:wght@400;500;600;700;800&display=swap');
:root{--ink:#252525;--muted:#717a90;--line:#dfe5f1;--accent:#4265d6;--paper:#f1f4fd;--white:#fff;--soft:#dde4fa}*{box-sizing:border-box}body{margin:0;background:var(--paper);color:var(--ink);font:15px/1.6 Manrope,Arial,sans-serif}button,input,textarea{font:inherit}button,a,input,textarea{ -webkit-tap-highlight-color:transparent}button,a{touch-action:manipulation}button{cursor:pointer}button:disabled{cursor:default;opacity:.55}a{color:inherit;text-decoration:none}h1,h2,h3,p{margin:0}h1{font-size:38px;line-height:1.25;letter-spacing:-1.3px}h2{font-size:24px;line-height:1.35;letter-spacing:-.5px}h3{font-size:19px;line-height:1.5}p{color:var(--muted)}button:focus-visible,a:focus-visible,input:focus-visible,textarea:focus-visible{outline:3px solid #9eb4fa;outline-offset:3px}.brand{font-size:27px;font-weight:800;letter-spacing:1px}.brand span{color:#b13d87}.eyebrow{display:block;font-size:11px;font-weight:800;letter-spacing:1.6px;text-transform:uppercase;color:var(--muted)}.primary,.secondary{display:inline-flex;align-items:center;justify-content:center;gap:20px;border-radius:12px;padding:13px 22px;font-weight:700;border:1px solid transparent}.primary{background:var(--accent);color:white}.primary:hover{background:#3554bc}.secondary{border-color:var(--line);background:white}.login{min-height:100dvh;display:grid;grid-template-columns:1fr 1fr;padding:22px;gap:22px}.welcome{min-height:660px;display:flex;flex-direction:column;justify-content:space-between;border-radius:26px;padding:48px 56px;background:radial-gradient(ellipse at 90% 80%,#a5baf2 0,transparent 60%),#e2e9fc;position:relative;overflow:hidden}.welcome h1{font-size:48px;margin:20px 0}.welcome p{max-width:390px;color:#687697}.welcome .eyebrow{color:#64769c}.welcome-tags{display:flex;flex-wrap:wrap;gap:10px;margin-top:30px}.welcome-tags span{padding:7px 12px;border:1px solid #b2c2ee;border-radius:30px;font-size:12px}.welcome small{color:#72809e}.login-side{display:flex;align-items:center;justify-content:center;padding:30px}.login-card{max-width:390px;width:100%}.login-card h2{font-size:32px;margin:10px 0 16px}.login-card p{margin-bottom:26px}.login-card label{display:block;font-weight:700;margin-bottom:9px}.login-card input{width:100%;padding:15px 16px;background:white;border:1px solid #dce3f3;border-radius:12px;color:var(--ink)}.login-card .hint{font-size:12px;margin:12px 0 24px}.login-card .primary{width:100%;justify-content:space-between}.error{color:#a63d67;font-size:13px}.support{display:block;text-align:center;margin-top:22px;font-size:13px;color:var(--muted)}.shell{display:grid;grid-template-columns:310px minmax(0,1fr);min-height:100dvh}.sidebar{background:#fff;border-right:1px solid var(--line);padding:32px 20px;position:sticky;top:0;height:100dvh;display:flex;flex-direction:column;overflow:auto}.sidebar .brand{padding:0 15px}.course-title{padding:38px 15px 26px}.course-title h2{font-size:18px;margin-top:8px}.topic{display:grid;grid-template-columns:18px minmax(0,1fr) 18px;gap:12px;align-items:start;text-align:left;width:100%;border:0;background:transparent;border-radius:12px;padding:14px 12px;margin-bottom:5px;color:var(--ink)}.topic:hover{background:#f1f4fd}.topic.active{background:var(--soft)}.topic-number{font-size:12px;color:#8594b5;padding-top:3px}.topic strong{display:block;font-size:13px;font-weight:700;line-height:1.5}.topic small{display:block;font-size:10px;color:var(--muted);margin-top:4px}.sidebar-bottom{margin-top:auto;padding:26px 15px 0;font-size:12px}.sidebar-bottom strong{float:right}.sidebar-bottom small{color:var(--muted);font-size:10px}progress{display:block;width:100%;height:6px;margin:12px 0;border:0;appearance:none}progress::-webkit-progress-bar{background:#e8edfa;border-radius:20px}progress::-webkit-progress-value{background:var(--accent);border-radius:20px}progress::-moz-progress-bar{background:var(--accent)}.main{max-width:1160px;width:100%;margin:auto;padding:0 50px 60px}header{display:flex;align-items:center;justify-content:space-between;min-height:100px;border-bottom:1px solid var(--line);gap:20px}.user{display:flex;align-items:center;gap:24px;font-size:12px}.user small{display:block;color:var(--muted);font-size:10px}.logout{border:1px solid var(--line);background:transparent;border-radius:9px;padding:7px 12px;font-size:12px;color:var(--muted)}.heading{padding:35px 0 28px}.heading h1{margin:12px 0;font-size:32px;max-width:760px}.heading p{font-size:13px}.lesson-tabs{display:flex;gap:8px;flex-wrap:wrap;margin-bottom:20px}.lesson-tabs button{padding:9px 17px;border:1px solid var(--line);border-radius:30px;background:transparent;color:var(--muted);font-size:12px}.lesson-tabs .selected{background:var(--ink);color:white;border-color:var(--ink)}.lesson-card{background:white;border:1px solid var(--line);border-radius:20px;padding:22px;display:grid;grid-template-columns:205px 1fr;gap:28px;align-items:center}.lesson-art{min-height:220px;border-radius:13px;padding:22px;background:radial-gradient(ellipse at 100% 0,#aec1fa,transparent 70%),#dde4fa;display:flex;flex-direction:column;justify-content:space-between}.lesson-art span{font-size:11px;font-weight:800;letter-spacing:1px}.lesson-art strong{font-size:64px;line-height:1;font-weight:500;letter-spacing:-4px}.lesson-art small{font-size:10px}.lesson-info h2{margin:12px 0}.lesson-info p{font-size:12px}.actions{display:flex;gap:8px;flex-wrap:wrap;margin-top:22px}.actions a{font-size:12px;padding:10px 14px}.section-heading{display:flex;align-items:center;justify-content:space-between;margin:32px 0 18px;gap:15px}.section-heading h2{font-size:21px}.section-heading span{font-size:11px;color:var(--muted)}.tasks{display:grid;gap:15px}.task-card{background:white;border:1px solid var(--line);border-radius:18px;padding:26px}.task-top{display:flex;justify-content:space-between;align-items:center;gap:12px;margin-bottom:18px}.badge{border-radius:20px;background:var(--soft);color:var(--accent);padding:4px 10px;font-size:10px}.badge.neutral{background:#f1f4fd;color:#697cba}fieldset{border:0;padding:0;margin:20px 0}.option{display:flex;align-items:center;gap:12px;padding:12px 16px;border:1px solid var(--line);border-radius:11px;margin-bottom:8px;font-size:13px;cursor:pointer}.option:has(input:checked){background:var(--soft);border-color:#a9bcf5}input[type=radio]{accent-color:var(--accent);flex-shrink:0}textarea{display:block;width:100%;min-height:115px;border:1px solid var(--line);border-radius:12px;padding:15px;resize:vertical;margin:20px 0;background:#f8faff;color:var(--ink)}.task-card .primary{font-size:12px;padding:11px 17px}.feedback{white-space:pre-line;font-size:13px;padding:15px;border-radius:10px;background:#f1f4fd;margin:16px 0;color:#586b9b}.feedback.correct{background:#e7edff;color:#3554bc}.locked{background:transparent;border-style:dashed}.locked p{font-size:12px;margin-top:8px}.locked-card{text-align:center;padding:65px 30px;background:white;border:1px solid var(--line);border-radius:20px}.locked-card h2{margin:12px 0}.locked-card p{font-size:13px;max-width:420px;margin:auto}.lock-icon{font-size:48px;color:#7797eb}.burger{display:none}.overlay{display:none}.loading{padding:80px;text-align:center}.sr-only{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0,0,0,0)}.toast{position:fixed;bottom:24px;right:24px;background:var(--ink);color:white;padding:16px 24px;border-radius:12px;z-index:10}.form-error{margin-top:10px}@media(min-width:1500px){.main{padding:0 70px 60px}}@media(max-width:1100px){.shell{grid-template-columns:270px minmax(0,1fr)}.main{padding:0 25px 40px}.lesson-card{grid-template-columns:145px 1fr;gap:20px}.lesson-art{min-height:210px}.welcome{padding:35px}.welcome h1{font-size:40px}}@media(max-width:760px){.login{display:block;padding:0}.welcome{min-height:auto;border-radius:0;padding:28px;gap:30px}.welcome h1{font-size:32px;margin:14px 0}.welcome p{font-size:13px}.welcome-tags{margin-top:18px}.welcome>small{display:none}.login-side{padding:35px 28px}.login-card h2{font-size:27px}.shell{display:block}.main{padding:0 20px 35px}.sidebar{position:fixed;left:0;top:0;width:290px;z-index:30;transform:translateX(-100%);transition:transform .2s}.sidebar.open{transform:translateX(0)}.overlay.visible{display:block;position:fixed;inset:0;background:#18245266;z-index:20}.burger{display:block;background:none;border:0;font-size:21px;color:var(--ink)}header{min-height:78px;gap:12px}header>.eyebrow{display:none}.user{gap:12px}.heading{padding:26px 0 20px}.heading h1{font-size:27px}.lesson-card{display:block;padding:18px}.lesson-art{min-height:130px;position:relative;margin-bottom:20px}.lesson-art strong{font-size:46px;position:absolute;right:22px;top:38px}.lesson-info h2{font-size:21px}.section-heading h2{font-size:19px}.task-card{padding:20px}.task-card h3{font-size:17px}.option{padding:11px;font-size:12px}.task-top{flex-wrap:wrap}.locked-card{padding:45px 22px}.welcome-tags span{font-size:10px}}

.topic>span:last-child{text-align:center;justify-self:center}

/* Palette inspired by proage-school.ru */
.brand{color:#253c88}.brand span{color:#b13d87}
.welcome{background:radial-gradient(ellipse at 90% 80%,#5479f755 0,transparent 65%),linear-gradient(135deg,#1b2b6e,#284593);color:#fff}
.welcome .brand{color:#fff}.welcome .eyebrow,.welcome p,.welcome small{color:#d4dffc}
.welcome-tags span{border-color:#8da8ef66;background:#ffffff08;color:#edf2ff}
.lesson-art{color:#253c88}.lesson-tabs .selected{background:#253c88;border-color:#253c88}

/* Compact learning workspace and readable answer states */
body{font-size:17px;line-height:1.55}.main{max-width:1280px;padding:0 32px 40px;margin:0 auto}header{min-height:64px}.heading{padding:18px 0 16px}.heading h1{margin:7px 0;font-size:32px;max-width:100%}.heading p{font-size:16px}.eyebrow{font-size:12px}.user,.logout{font-size:14px}.user small{font-size:12px}.course-title{padding:24px 12px 18px}.topic strong{font-size:15px}.topic small,.topic-number{font-size:12px}.sidebar-bottom{font-size:14px}.sidebar-bottom small{font-size:12px}.lesson-tabs{margin-bottom:14px}.lesson-tabs button{font-size:15px;padding:8px 16px}.lesson-card{padding:18px;grid-template-columns:96px 1fr;gap:20px}.lesson-art{min-height:130px;padding:14px}.lesson-art strong{font-size:40px}.lesson-art small{font-size:11px}.lesson-info h2{margin:6px 0;font-size:25px}.lesson-info>.eyebrow{display:none}.lesson-info p{font-size:16px}.actions{margin-top:14px}.actions a,.task-card .primary{font-size:16px}.section-heading{margin:22px 0 12px}.section-heading span{font-size:14px}.task-card{padding:22px}.task-top{margin-bottom:12px}.task-card h3{font-size:22px}.badge{font-size:12px}.option{font-size:17px;padding:13px 16px;flex-wrap:wrap}.option span{flex:1;min-width:150px}.option.answer-correct{border-color:#5479f7;background:#eef3ff}.answer-correct>span{text-decoration:underline;text-decoration-color:#4265d6;text-underline-offset:5px;text-decoration-thickness:2px}.answer-mark{font-size:13px;color:#3554bc}.feedback{font-size:16px}.answer-label{display:block;font-weight:700;margin-top:16px}.saved-answer{white-space:pre-wrap;overflow-wrap:anywhere;padding:16px;border:1px solid var(--line);border-radius:12px;background:#f8faff;margin:10px 0}.locked p{font-size:15px}fieldset:disabled{opacity:1}textarea:disabled{opacity:1}
@media(min-width:1500px){.main{padding:0 36px 40px}}
@media(max-width:760px){.main{padding:0 16px 30px}header{min-height:60px}.heading{padding:16px 0 12px}.heading h1{font-size:26px}.lesson-card{display:grid;grid-template-columns:1fr;padding:16px}.lesson-art{display:none}.lesson-info h2{font-size:23px}.task-card{padding:18px}.task-card h3{font-size:20px}.option{font-size:16px;padding:12px}.user{gap:8px}.sidebar{width:min(320px,90vw)}}